struct load_url_result *load_url_async(void *ctx, struct pb_url *url,
load_url_complete async_cb, void *async_data,
waiter_cb stdout_cb, void *stdout_data)
struct load_url_result *load_url_async(void *ctx, struct pb_url *url,
load_url_complete async_cb, void *async_data,
waiter_cb stdout_cb, void *stdout_data)